Embodiments of the present disclosure provide methods, apparatuses and computer program products for enabling efficient uplink data transmission in a wireless communication system. A method implemented at a user equipment (UE) includes: receiving an uplink grant from a network node, the uplink grant indicating a granted resource associated with a plurality of channels; detecting availability of the plurality of channels; determining an uplink transmission parameter based on the uplink grant and a result from the detection; and transmitting data to the network node according to the determined uplink transmission parameter. Embodiments of the present disclosure may enable adaptive uplink transmission and increase uplink transmission opportunity.